| Step | Hyp | Ref | Expression | 
|---|
| 1 |  | nfdisj1 5123 | . . . 4
⊢
Ⅎ𝑥Disj
𝑥 ∈ 𝐴 𝐵 | 
| 2 |  | nfcv 2904 | . . . . 5
⊢
Ⅎ𝑥𝑦 | 
| 3 |  | disjabrexf.1 | . . . . . . . . . . 11
⊢
Ⅎ𝑥𝐴 | 
| 4 | 3 | nfcri 2896 | . . . . . . . . . 10
⊢
Ⅎ𝑥 𝑖 ∈ 𝐴 | 
| 5 |  | nfcsb1v 3922 | . . . . . . . . . . 11
⊢
Ⅎ𝑥⦋𝑖 / 𝑥⦌𝐵 | 
| 6 | 5 | nfcri 2896 | . . . . . . . . . 10
⊢
Ⅎ𝑥 𝑗 ∈ ⦋𝑖 / 𝑥⦌𝐵 | 
| 7 | 4, 6 | nfan 1898 | . . . . . . . . 9
⊢
Ⅎ𝑥(𝑖 ∈ 𝐴 ∧ 𝑗 ∈ ⦋𝑖 / 𝑥⦌𝐵) | 
| 8 | 7 | nfab 2910 | . . . . . . . 8
⊢
Ⅎ𝑥{𝑖 ∣ (𝑖 ∈ 𝐴 ∧ 𝑗 ∈ ⦋𝑖 / 𝑥⦌𝐵)} | 
| 9 | 8 | nfuni 4913 | . . . . . . 7
⊢
Ⅎ𝑥∪ {𝑖
∣ (𝑖 ∈ 𝐴 ∧ 𝑗 ∈ ⦋𝑖 / 𝑥⦌𝐵)} | 
| 10 | 9 | nfcsb1 3921 | . . . . . 6
⊢
Ⅎ𝑥⦋∪
{𝑖 ∣ (𝑖 ∈ 𝐴 ∧ 𝑗 ∈ ⦋𝑖 / 𝑥⦌𝐵)} / 𝑥⦌𝐵 | 
| 11 | 10 | nfeq1 2920 | . . . . 5
⊢
Ⅎ𝑥⦋∪
{𝑖 ∣ (𝑖 ∈ 𝐴 ∧ 𝑗 ∈ ⦋𝑖 / 𝑥⦌𝐵)} / 𝑥⦌𝐵 = 𝑦 | 
| 12 | 2, 11 | nfralw 3310 | . . . 4
⊢
Ⅎ𝑥∀𝑗 ∈ 𝑦 ⦋∪
{𝑖 ∣ (𝑖 ∈ 𝐴 ∧ 𝑗 ∈ ⦋𝑖 / 𝑥⦌𝐵)} / 𝑥⦌𝐵 = 𝑦 | 
| 13 |  | eqeq2 2748 | . . . . 5
⊢ (𝑦 = 𝐵 → (⦋∪ {𝑖
∣ (𝑖 ∈ 𝐴 ∧ 𝑗 ∈ ⦋𝑖 / 𝑥⦌𝐵)} / 𝑥⦌𝐵 = 𝑦 ↔ ⦋∪ {𝑖
∣ (𝑖 ∈ 𝐴 ∧ 𝑗 ∈ ⦋𝑖 / 𝑥⦌𝐵)} / 𝑥⦌𝐵 = 𝐵)) | 
| 14 | 13 | raleqbi1dv 3337 | . . . 4
⊢ (𝑦 = 𝐵 → (∀𝑗 ∈ 𝑦 ⦋∪
{𝑖 ∣ (𝑖 ∈ 𝐴 ∧ 𝑗 ∈ ⦋𝑖 / 𝑥⦌𝐵)} / 𝑥⦌𝐵 = 𝑦 ↔ ∀𝑗 ∈ 𝐵 ⦋∪
{𝑖 ∣ (𝑖 ∈ 𝐴 ∧ 𝑗 ∈ ⦋𝑖 / 𝑥⦌𝐵)} / 𝑥⦌𝐵 = 𝐵)) | 
| 15 |  | vex 3483 | . . . . 5
⊢ 𝑦 ∈ V | 
| 16 | 15 | a1i 11 | . . . 4
⊢
(Disj 𝑥
∈ 𝐴 𝐵 → 𝑦 ∈ V) | 
| 17 |  | simplll 774 | . . . . . . . . . . . . 13
⊢
((((Disj 𝑥
∈ 𝐴 𝐵 ∧ 𝑥 ∈ 𝐴) ∧ 𝑗 ∈ 𝐵) ∧ (𝑖 ∈ 𝐴 ∧ 𝑗 ∈ ⦋𝑖 / 𝑥⦌𝐵)) → Disj 𝑥 ∈ 𝐴 𝐵) | 
| 18 |  | simpllr 775 | . . . . . . . . . . . . 13
⊢
((((Disj 𝑥
∈ 𝐴 𝐵 ∧ 𝑥 ∈ 𝐴) ∧ 𝑗 ∈ 𝐵) ∧ (𝑖 ∈ 𝐴 ∧ 𝑗 ∈ ⦋𝑖 / 𝑥⦌𝐵)) → 𝑥 ∈ 𝐴) | 
| 19 |  | simprl 770 | . . . . . . . . . . . . 13
⊢
((((Disj 𝑥
∈ 𝐴 𝐵 ∧ 𝑥 ∈ 𝐴) ∧ 𝑗 ∈ 𝐵) ∧ (𝑖 ∈ 𝐴 ∧ 𝑗 ∈ ⦋𝑖 / 𝑥⦌𝐵)) → 𝑖 ∈ 𝐴) | 
| 20 |  | simplr 768 | . . . . . . . . . . . . 13
⊢
((((Disj 𝑥
∈ 𝐴 𝐵 ∧ 𝑥 ∈ 𝐴) ∧ 𝑗 ∈ 𝐵) ∧ (𝑖 ∈ 𝐴 ∧ 𝑗 ∈ ⦋𝑖 / 𝑥⦌𝐵)) → 𝑗 ∈ 𝐵) | 
| 21 |  | simprr 772 | . . . . . . . . . . . . 13
⊢
((((Disj 𝑥
∈ 𝐴 𝐵 ∧ 𝑥 ∈ 𝐴) ∧ 𝑗 ∈ 𝐵) ∧ (𝑖 ∈ 𝐴 ∧ 𝑗 ∈ ⦋𝑖 / 𝑥⦌𝐵)) → 𝑗 ∈ ⦋𝑖 / 𝑥⦌𝐵) | 
| 22 |  | csbeq1a 3912 | . . . . . . . . . . . . . 14
⊢ (𝑥 = 𝑖 → 𝐵 = ⦋𝑖 / 𝑥⦌𝐵) | 
| 23 | 3, 5, 22 | disjif2 32595 | . . . . . . . . . . . . 13
⊢
((Disj 𝑥
∈ 𝐴 𝐵 ∧ (𝑥 ∈ 𝐴 ∧ 𝑖 ∈ 𝐴) ∧ (𝑗 ∈ 𝐵 ∧ 𝑗 ∈ ⦋𝑖 / 𝑥⦌𝐵)) → 𝑥 = 𝑖) | 
| 24 | 17, 18, 19, 20, 21, 23 | syl122anc 1380 | . . . . . . . . . . . 12
⊢
((((Disj 𝑥
∈ 𝐴 𝐵 ∧ 𝑥 ∈ 𝐴) ∧ 𝑗 ∈ 𝐵) ∧ (𝑖 ∈ 𝐴 ∧ 𝑗 ∈ ⦋𝑖 / 𝑥⦌𝐵)) → 𝑥 = 𝑖) | 
| 25 |  | simpr 484 | . . . . . . . . . . . . . 14
⊢
((((Disj 𝑥
∈ 𝐴 𝐵 ∧ 𝑥 ∈ 𝐴) ∧ 𝑗 ∈ 𝐵) ∧ 𝑥 = 𝑖) → 𝑥 = 𝑖) | 
| 26 |  | simpllr 775 | . . . . . . . . . . . . . 14
⊢
((((Disj 𝑥
∈ 𝐴 𝐵 ∧ 𝑥 ∈ 𝐴) ∧ 𝑗 ∈ 𝐵) ∧ 𝑥 = 𝑖) → 𝑥 ∈ 𝐴) | 
| 27 | 25, 26 | eqeltrrd 2841 | . . . . . . . . . . . . 13
⊢
((((Disj 𝑥
∈ 𝐴 𝐵 ∧ 𝑥 ∈ 𝐴) ∧ 𝑗 ∈ 𝐵) ∧ 𝑥 = 𝑖) → 𝑖 ∈ 𝐴) | 
| 28 |  | simplr 768 | . . . . . . . . . . . . . 14
⊢
((((Disj 𝑥
∈ 𝐴 𝐵 ∧ 𝑥 ∈ 𝐴) ∧ 𝑗 ∈ 𝐵) ∧ 𝑥 = 𝑖) → 𝑗 ∈ 𝐵) | 
| 29 | 22 | eleq2d 2826 | . . . . . . . . . . . . . . 15
⊢ (𝑥 = 𝑖 → (𝑗 ∈ 𝐵 ↔ 𝑗 ∈ ⦋𝑖 / 𝑥⦌𝐵)) | 
| 30 | 25, 29 | syl 17 | . . . . . . . . . . . . . 14
⊢
((((Disj 𝑥
∈ 𝐴 𝐵 ∧ 𝑥 ∈ 𝐴) ∧ 𝑗 ∈ 𝐵) ∧ 𝑥 = 𝑖) → (𝑗 ∈ 𝐵 ↔ 𝑗 ∈ ⦋𝑖 / 𝑥⦌𝐵)) | 
| 31 | 28, 30 | mpbid 232 | . . . . . . . . . . . . 13
⊢
((((Disj 𝑥
∈ 𝐴 𝐵 ∧ 𝑥 ∈ 𝐴) ∧ 𝑗 ∈ 𝐵) ∧ 𝑥 = 𝑖) → 𝑗 ∈ ⦋𝑖 / 𝑥⦌𝐵) | 
| 32 | 27, 31 | jca 511 | . . . . . . . . . . . 12
⊢
((((Disj 𝑥
∈ 𝐴 𝐵 ∧ 𝑥 ∈ 𝐴) ∧ 𝑗 ∈ 𝐵) ∧ 𝑥 = 𝑖) → (𝑖 ∈ 𝐴 ∧ 𝑗 ∈ ⦋𝑖 / 𝑥⦌𝐵)) | 
| 33 | 24, 32 | impbida 800 | . . . . . . . . . . 11
⊢
(((Disj 𝑥
∈ 𝐴 𝐵 ∧ 𝑥 ∈ 𝐴) ∧ 𝑗 ∈ 𝐵) → ((𝑖 ∈ 𝐴 ∧ 𝑗 ∈ ⦋𝑖 / 𝑥⦌𝐵) ↔ 𝑥 = 𝑖)) | 
| 34 |  | equcom 2016 | . . . . . . . . . . 11
⊢ (𝑥 = 𝑖 ↔ 𝑖 = 𝑥) | 
| 35 | 33, 34 | bitrdi 287 | . . . . . . . . . 10
⊢
(((Disj 𝑥
∈ 𝐴 𝐵 ∧ 𝑥 ∈ 𝐴) ∧ 𝑗 ∈ 𝐵) → ((𝑖 ∈ 𝐴 ∧ 𝑗 ∈ ⦋𝑖 / 𝑥⦌𝐵) ↔ 𝑖 = 𝑥)) | 
| 36 | 35 | abbidv 2807 | . . . . . . . . 9
⊢
(((Disj 𝑥
∈ 𝐴 𝐵 ∧ 𝑥 ∈ 𝐴) ∧ 𝑗 ∈ 𝐵) → {𝑖 ∣ (𝑖 ∈ 𝐴 ∧ 𝑗 ∈ ⦋𝑖 / 𝑥⦌𝐵)} = {𝑖 ∣ 𝑖 = 𝑥}) | 
| 37 |  | df-sn 4626 | . . . . . . . . 9
⊢ {𝑥} = {𝑖 ∣ 𝑖 = 𝑥} | 
| 38 | 36, 37 | eqtr4di 2794 | . . . . . . . 8
⊢
(((Disj 𝑥
∈ 𝐴 𝐵 ∧ 𝑥 ∈ 𝐴) ∧ 𝑗 ∈ 𝐵) → {𝑖 ∣ (𝑖 ∈ 𝐴 ∧ 𝑗 ∈ ⦋𝑖 / 𝑥⦌𝐵)} = {𝑥}) | 
| 39 | 38 | unieqd 4919 | . . . . . . 7
⊢
(((Disj 𝑥
∈ 𝐴 𝐵 ∧ 𝑥 ∈ 𝐴) ∧ 𝑗 ∈ 𝐵) → ∪ {𝑖 ∣ (𝑖 ∈ 𝐴 ∧ 𝑗 ∈ ⦋𝑖 / 𝑥⦌𝐵)} = ∪ {𝑥}) | 
| 40 |  | unisnv 4926 | . . . . . . 7
⊢ ∪ {𝑥}
= 𝑥 | 
| 41 | 39, 40 | eqtrdi 2792 | . . . . . 6
⊢
(((Disj 𝑥
∈ 𝐴 𝐵 ∧ 𝑥 ∈ 𝐴) ∧ 𝑗 ∈ 𝐵) → ∪ {𝑖 ∣ (𝑖 ∈ 𝐴 ∧ 𝑗 ∈ ⦋𝑖 / 𝑥⦌𝐵)} = 𝑥) | 
| 42 |  | csbeq1 3901 | . . . . . . 7
⊢ (∪ {𝑖
∣ (𝑖 ∈ 𝐴 ∧ 𝑗 ∈ ⦋𝑖 / 𝑥⦌𝐵)} = 𝑥 → ⦋∪ {𝑖
∣ (𝑖 ∈ 𝐴 ∧ 𝑗 ∈ ⦋𝑖 / 𝑥⦌𝐵)} / 𝑥⦌𝐵 = ⦋𝑥 / 𝑥⦌𝐵) | 
| 43 |  | csbid 3911 | . . . . . . 7
⊢
⦋𝑥 /
𝑥⦌𝐵 = 𝐵 | 
| 44 | 42, 43 | eqtrdi 2792 | . . . . . 6
⊢ (∪ {𝑖
∣ (𝑖 ∈ 𝐴 ∧ 𝑗 ∈ ⦋𝑖 / 𝑥⦌𝐵)} = 𝑥 → ⦋∪ {𝑖
∣ (𝑖 ∈ 𝐴 ∧ 𝑗 ∈ ⦋𝑖 / 𝑥⦌𝐵)} / 𝑥⦌𝐵 = 𝐵) | 
| 45 | 41, 44 | syl 17 | . . . . 5
⊢
(((Disj 𝑥
∈ 𝐴 𝐵 ∧ 𝑥 ∈ 𝐴) ∧ 𝑗 ∈ 𝐵) → ⦋∪ {𝑖
∣ (𝑖 ∈ 𝐴 ∧ 𝑗 ∈ ⦋𝑖 / 𝑥⦌𝐵)} / 𝑥⦌𝐵 = 𝐵) | 
| 46 | 45 | ralrimiva 3145 | . . . 4
⊢
((Disj 𝑥
∈ 𝐴 𝐵 ∧ 𝑥 ∈ 𝐴) → ∀𝑗 ∈ 𝐵 ⦋∪
{𝑖 ∣ (𝑖 ∈ 𝐴 ∧ 𝑗 ∈ ⦋𝑖 / 𝑥⦌𝐵)} / 𝑥⦌𝐵 = 𝐵) | 
| 47 | 1, 12, 14, 16, 46 | elabreximd 32530 | . . 3
⊢
((Disj 𝑥
∈ 𝐴 𝐵 ∧ 𝑦 ∈ {𝑧 ∣ ∃𝑥 ∈ 𝐴 𝑧 = 𝐵}) → ∀𝑗 ∈ 𝑦 ⦋∪
{𝑖 ∣ (𝑖 ∈ 𝐴 ∧ 𝑗 ∈ ⦋𝑖 / 𝑥⦌𝐵)} / 𝑥⦌𝐵 = 𝑦) | 
| 48 | 47 | ralrimiva 3145 | . 2
⊢
(Disj 𝑥
∈ 𝐴 𝐵 → ∀𝑦 ∈ {𝑧 ∣ ∃𝑥 ∈ 𝐴 𝑧 = 𝐵}∀𝑗 ∈ 𝑦 ⦋∪
{𝑖 ∣ (𝑖 ∈ 𝐴 ∧ 𝑗 ∈ ⦋𝑖 / 𝑥⦌𝐵)} / 𝑥⦌𝐵 = 𝑦) | 
| 49 |  | invdisj 5128 | . 2
⊢
(∀𝑦 ∈
{𝑧 ∣ ∃𝑥 ∈ 𝐴 𝑧 = 𝐵}∀𝑗 ∈ 𝑦 ⦋∪
{𝑖 ∣ (𝑖 ∈ 𝐴 ∧ 𝑗 ∈ ⦋𝑖 / 𝑥⦌𝐵)} / 𝑥⦌𝐵 = 𝑦 → Disj 𝑦 ∈ {𝑧 ∣ ∃𝑥 ∈ 𝐴 𝑧 = 𝐵}𝑦) | 
| 50 | 48, 49 | syl 17 | 1
⊢
(Disj 𝑥
∈ 𝐴 𝐵 → Disj 𝑦 ∈ {𝑧 ∣ ∃𝑥 ∈ 𝐴 𝑧 = 𝐵}𝑦) |